(1) Field of the Invention
The invention relates to a method for sinking a borehole in the ground, a wet boring or drilling tool and a boring or drilling plant.
Fundamentally a distinction is made between two methods, namely dry and wet boring when carrying out boring operations, such as pile foundations.
As the wet boring method involves greater expenditure with respect to the site equipment and restricted boring plant mobility, wherever it is possible use is made of the dry boring method involving the employment of a boring implement on caterpillar carriers or supports. However, when particularly hard geologies are encountered, said method also has limitations. Compared with wet boring, the boring capacity and boring tool wear increase significantly.
(2) Description of Related Art
If a pile bore wall has to e.g. be anchored in rock, the boring rate in the non-rocky substrate is very good in the case of dry boring, but in rock is only a fraction of the normal rate. There is also very significant wear. Only in very rare cases is it possible to convert to the wet boring method, because both the equipment and personnel are not present on site for correctly setting up a wet boring plant.
DE 197 02 533 A1 discloses the relevant prior art. The core bit is either flushed with air or a boring or drilling mud. DE 197 02 533 A1 teaches supplying the core bit by means of a pipe with boring mud from a reservoir located outside the borehole. A fluid flow is produced by means of a hose pump.
Such a known device requires a comparatively complex arrangement of pipes, pumps and fluid reservoirs inside and outside the borehole.
The object of the invention is to provide a method for sinking a borehole in the ground, a wet boring tool and a boring plant permitting a simplified performance of a wet boring method.